JPS5894472A - Cleaner for ink jet recorder - Google Patents

Abstract

PURPOSE:To easily remove dirt on a nozzle surface, by a method wherein a cleaner is provided at a position outside of a recording range on a main scanning path of a carriage, and the cleaner is provided with a driving device for advancing it to an advanced position and retracting it to a retracted position. CONSTITUTION:The cleaner 16 is provided at a position outside of the recording range of the main scanning path of the carriage 13 having an ink jet head 14 mounted thereon, which position is in a section (a) (where the head 14 is accelerated or decelerated) between the carriage 13 and a starting position S'. The cleaner 16 is provided with the driving device for advancing it to the advanced position D at the time of cleaning the nozzle surface of the head 14 and retracting it to the retracted position C at other times. For example, the driving device is comprised of a solenoid 18, a plunger 19, a spring 20 and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning device for an inkjet recording device that is particularly effective in a recording device in which a recording head moves at a high speed, such as a flat scanning type recording device.

FIG. 1 is a sectional view of a typical inkjet head. When an electric pulse is applied to the pressure generating means consisting of the piezo element 1 and the vibrator 2, the volume of the pressure chamber 3 changes. This volume change pressurizes the ink, and ink droplets 6 are ejected from the ejection nozzle 4, and a recorded image by the ink droplets 6 is obtained on the opposing recording paper. Incidentally, since the ink droplet 6 is minute, with a diameter of several tens of microns, a part of the ink droplet 5 colliding with the recording paper bounces back toward the recording head e, and as a result, the ink droplet 7 hits the recording head 6. The front of the will get dirty. Since the distance between the recording head 6 and the recording paper is generally several ml, 11, if the recording head 6 becomes dirty, the recording paper will also become dirty, leading to a decrease in the quality of the recorded image. Furthermore, if the amount of ink liquid 7 increases, it may block the ejection nozzle 4.
In some cases, it may become impossible to record.

FIG. 2 shows an example of a conventional cleaning device for removing such dirt from a recording head. The figure shows a part of a cylindrical scanning type recording device, in which a cleaner 1o is provided on the side of a drum 8 around which a recording paper 9 is wound. Cleaner 1
0 was fixed to a fixed plate 11, and the tip of the cleaner 10 was in contact with the surface of the recording head 6 to remove ink 7 adhering to the surface. The cleaner 1o is made of rubber or polymeric material with moderate elasticity.

As recording ends, the carriage 12 moves to the left, and during this movement, the cleaner 10 is brought into contact with the recording head 1o to clean the surface of the recording head. This leaning method, like a cylindrical scanning recording device,
This was effective when the moving speed of the recording head 6 was relatively slow. Furthermore, since the recording head 6 moves to the left starting position each time recording is completed, the recording head 6 can be cleaned using this movement.

However, this is not suitable for a plane scanning type recording device in which the recording head 6 moves at extremely high speed. That is,
In the plane scanning type recording apparatus, since the moving speed of the carriage that moves the recording head 6 is extremely high, a large force impact is applied to the recording head 6 when the cleaner 1o and the recording head 6 come into contact with each other.

This impact causes undesirable problems such as ink droplets being ejected from the nozzles 4 of the recording head e, or air being sucked in from the nozzles 4. Further, the cleaner 1o is also subjected to impact, causing problems such as damage to the cleaner 1o. As described above, when the moving speed of the carriage is extremely high, the conventional cleaning method is not sufficiently effective. Furthermore, there is currently no suitable leaning method in sight. For this reason, in a plane scanning type recording apparatus in which the recording head 6 moves at high speed, an appropriate leaning method has been desired.

The present invention has been made from this point of view, and provides an effective leaning method.

FIG. 3 shows an embodiment of the cleaning device according to the present invention. FIG. 3a shows a plane scanning type recording device in which the recording head moves at an extremely high speed, and the recording head 14 on the carriage 13 repeatedly moves back and forth in the left-right direction (that is, in the main scanning direction), while repeatedly moving paper 1
Print on 5. In order to smoothly perform such reciprocating movement, the carriage 13 accelerates and decelerates at both ends.
At the center, the speed is constant. If we classify the former as an acceleration/deceleration section and the latter as a constant velocity section, printing is performed in a nearly constant velocity section. The moving speed of the carriage 13 corresponding to the position of the carriage 13 shown in FIG. The cleaner 16 is provided in the acceleration/deceleration section A. The cleaner 16 is fixed to a mounting plate 17, and the mounting plate 17 is connected to a plunger 19 of a solenoid 18. A spring 2o is attached to one end of the mounting plate 17, and the tension of the spring 20 holds the cylinder 16 at the rear position C. When a constant voltage is applied to the solenoid 18, a force is induced in the plunger 19 that overcomes the tension of the spring 2o, and the cleaner 16 is held in the forward position. The cleaner 16 has such a movable mechanism. The recording head 14 starts moving from the start position S and performs printing by repeatedly moving back and forth a plurality of times, but the cleaner 16 is held at the rear position C during this time.

After printing is completed, the recording head 14 moves again to the start position S, and at this position it prepares for the next printing or comes to a halt. In the present invention, immediately before entering such a state, the recording head 14 is cleaned using the time when the acceleration/deceleration section A is passed. First, immediately before or after the carriage 13 moves to the acceleration/deceleration section A, the solenoid 18
By operating the cleaner 16, the cleaner 16 is moved from the rear position C to the front position and held there. In the front position, the tip of the cleaner 16 is located above the space in which the recording head 14 moves. Therefore, when the carriage 13 moves from the right, the moving recording head 14 comes into contact with the stationary cleaner 16, and the ink on the surface of the recording head 14 is wiped off. The cleaner 16 is held at the front position from the time when the recording head 14 starts contacting with the cleaner 16 until the time when the contact ends. After the contact is completely completed, the operation of the solenoid 1B is turned off, and as a result, the cleaner 16 is moved to the rear position C by the tension of the spring 2o. The recording head 14 is cleaned in this manner.

Since the installation position of the cleaner 16 is in the acceleration/deceleration section A, even when the moving speed of the recording head 14 during printing is extremely fast, the speed Vo when the cleaner 16 and the recording head 14 come into contact can be kept low. . As a result, the cleaner 16 is damaged.

Problems such as impact on the recording head 14 can be eliminated.

If the cleaner 16 is installed further to the left, -
The moving speed of the carriage 13 is further reduced, and the recording head 14 can be cleaned more stably.

Since it is still necessary to keep the external dimensions of the main body small, acceleration/deceleration section A is a short section. For this reason, a large inertial force acts on the carriage 13 within this section, and the speed vO when the recording head 14 and the cleaner 16 come into contact is
is extremely unstable.

Unfortunately, it is also difficult to control the speed vO stably.

FIG. 3C shows an embodiment that solves this problem, in which the deceleration start position of the carriage 13 is set to the right only when cleaning the recording head 14, and the area of the acceleration/deceleration section A is widened.

Therefore, the speed Vo at which the recording head 14 and cleaner 16 come into contact becomes low, and the recording head 14 can be cleaned in a stable state.

FIG. 3d shows still another embodiment of the present invention, in which a constant velocity section 2 is provided within the area of the acceleration/deceleration section A. If the acceleration/deceleration section A is wide, the constant velocity section 2 can be sufficiently secured. By providing the constant velocity section 2, the velocity vO can be controlled more stably, and recording heads >4 can be cleaned more effectively. The presence of constant velocity section 2 is also effective when increasing the number of pleats at the tip of the cleaner 16 to increase the cleaning effect, or when cleaning more effectively because the surface of the recording head 140 is relatively large.

These sections can be easily adjusted by controlling the acceleration of the carriage 13.

FIGS. 4a and 4b are a block circuit diagram and a timing chart showing the circuit operation of the control system in the above embodiment of the present invention.

Upon completion of printing, the recording head 14 moves in the acceleration/deceleration period A direction, and at this time, the cleaning start timing detection circuit 21 sends the signal a generated by the
2 and applies a drive signal to the solenoid 23.

By inputting this drive signal, the cleaner 16 is held at the front position and waits for the recording head 14 to come into contact with it.

The acceleration/deceleration section of the carriage 13 is A as shown in FIG. 4, and within this section there is a constant velocity section 2. Within the second section, the cleaner 1e and the recording head 14 come into contact and the recording head 14 is cleaned. After cleaning the recording head °14, the signal C is input to the flip-flop 22 by detecting the position of the head movement or as a function of time, and the drive signal of the solenoid 23 is turned OFF, so that the cleaner 16 moves backward. It is held in position C. Cleaning is performed in section E.

As described above, the cleaning device for an inkjet recording device according to the present invention includes a cleaner that wipes and cleans the surface of the recording head at a position outside the printing range in an inkjet recording device that performs recording while moving the recording head in the main scanning direction. During printing, this cleaner is held at a rear position where it does not come into contact with the recording head, and after printing is completed, it is moved to the front position and held there, and as the carriage moves, the recording head and cleaner are brought into contact and the cleaner is placed on the recording head surface. Since the cleaner is moved to the rear position after cleaning is completed, it is possible to clean the recording head well even in a plane scanning type recording apparatus in which the recording head moves at high speed.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a recording head used in the present invention, FIG. 2 is a front view of a cleaning device of a conventional cylindrical scanning type inkjet recording device, and FIG. 3a is a cross-sectional view of an inkjet recording device according to the present invention. A front view showing an embodiment of the cleaning device, d is an explanatory diagram of its operation, and FIG.
1 is a block diagram showing an example of a drive circuit for a cleaning device according to the present invention, and also a timing chart thereof. e, 14...recording head, 10.16...
...Cleaner, 12, 13... Carriage, 1
7...Mounting plate, 18...Solenoid,
19... Plunger, 20... Spring, 22... Flip 70 knob. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure-2 Condolence Figure 3 Cα) = 1 [shi]

Claims (4)

[Claims] (1) A cleaner placed outside the recording range of an inkjet recording apparatus that performs recording while moving a carriage with a fixed recording head in the main scanning direction, and a first cleaner that does not allow the cleaner to come into contact with the recording head during recording operation. A cleaning device for an inkjet recording apparatus, comprising means for holding the cleaner at a second position where the cleaner can come into contact with a recording head after a recording operation is completed. (2) A cleaning device for an inkjet recording apparatus according to claim 1, wherein a section for accelerating and decelerating the movement of the recording head is formed at a position outside the recording range, and a cleaner is disposed within this section. (3) The cleaning device for an inkjet recording apparatus according to claim 2, wherein the acceleration/deceleration section is widened only when cleaning the recording head. (4) A cleaning device for an inkjet recording apparatus according to claim 3, wherein a part of the acceleration/deceleration section is a constant velocity section, and a cleaner is disposed within this section.